Surface-modified nanopore glass membrane as electrolyte for DMFCs

A porous glass membrane modified with sulfonic acid groups was evaluated as a proton-conducting electrolyte in direct methanol fuel cells (DMFCs), and the performance was examined. The cell performance was characterized by voltage vs. current measurements, electrochemical impedance spectroscopy, and methanol permeation (crossover) measurements. When diluted methanol (3 M) was supplied to the cell, the porous glass membrane showed inferior performance compared to Nafion due to lower conductivity of the porous glass membrane. However, the porous glass membrane showed better performance with a 17.5 M methanol solution than the Nafion membrane. This better performance of the porous glass membrane is due to the lower methanol permeation in concentrated methanol solutions.